Effect of Supplementary Irrigation on the Yield of Sorghum (Sorghum bicolor L. Moench) in the Context of Climate Change in the Dry Savannahs of Togo

Under the current context of climate change, supplementary irrigation may be needed for crop production resilience. We determined the effects of supplementary irrigation on sorghum grain yield in the dry Savannah region of Togo. A two-year trial was conducted in a controlled environment at AREJ, an agro-ecological center in Cinkassé. The plant material was sorghum variety Sorvato 28. The experimental design was a Completely Randomized Block with three replications and three treatments as follows: T0 control plot (rainfed conditions);T1 (supplementary irrigation from flowering to grain filling stage) and T2 (supplementary irrigation from planting to grain filling stage). Two irrigation techniques (furrow and Californian system) were used under each watering treatment. The results showed that irrigation technique significantly affected panicle length with no effect on 1000 grains mass. Panicle length and grain yields varied from 15.59 to 25.71 cm and 0.0 to 2.06 t∙h−1, respectively, with the highest values (25.66 cm and 2.06 t∙h−1, respectively) under the T2 treatment with the California system-based supplementary irrigation. The comparison of results obtained on treatment T0 and T2, shows that supplementary irrigation increased the yields by at least 68.62%. Supplementary irrigation during sowing and growing season (T2) improved sorghum yields in the dry savannahs of Togo, with a better performance of the California irrigation system.

Short-Term Effect of Grazing Exclusion and Uncontrolled Grazing on Species Abundance, Dry Matter Yield and Nutritive Value in an Invaded Area by Euryops floribundus in the Eastern Cape, South Africa

Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangeland on relative frequency, dry matter yield and nutritive value of dominant grasses in an area invaded by Euryops floribundus. A plot of 2.5 ha was measured and the boundaries demarcated using tape measure and steal pins, the plot was further divided into two subplots of 1ha each which were 5 m apart. One subplot was fenced and protected from grazing livestock, while one subplot was grazed continuously and not fenced. Three parallel belt transects of 100 m × 2 m with 3 m apart were laid out in both subplots. Woody plants occurring within the transects were identified and recorded to determine density. In each subplot, a 0.25 m2 quadrant measuring was thrown randomly to take detailed records on plant species, relative frequency of species and herbage biomass. Four dominant species at the two sites were harvested to determine the nutritive value. Results indicate that grazing exclusion (GE) facilitates grass species diversity, subsequently sixteen and thirteen grasses species were recorded in the GE and uncontrolled grazed (UG) sites, respectively. Eragrostis chloromelas (21.7%), and Themeda triandra (13.2%) had high relative frequencies in the GE site. Highest biomass production was recorded in the GE site (1400 kg·ha-1) compared to UG site (1102 kg·ha-1). Crude protein content was relatively lower at UG site (5.4% - 5.8%) as compared to GE site (7.2% - 7.8%). It was concluded that, GE showed a positive impact on a relative frequency (%), dry matter yield and crude protein content. UG creates a conducive environment for Euryops recruitment. Further studies are required to examine the impact of GE in long-term trial setup.

Effects of Cutting Interval between Harvests on Dry Matter Yield and Nutritive Value in Alfalfa

Understanding the relationship between dry matter yield and nutritive value throughout the growing season will help optimize the cutting intervals between harvests in alfalfa (Medicago sativa L.). The Ogallala Aquifer is a very important water source when growing alfalfa in Southwest Kansas and unfortunately, the water level of the Ogallala Aquifer is shrinking. The objective of this study was to determine the optimum cutting interval that optimizes dry matter yield and nutritive values of alfalfa. Alfalfa was harvested with different cutting intervals, i.e., every 28, 35, 42 and 49 day, which was equivalent of 5, 4, 4, and 3 cuttings per year, respectively in 2013 and 2014. Based on 2-yr total yield, by delaying alfalfa harvest by 21 days, i.e., from every 28th day to 49th day, alfalfa yield increased by 2.25 Mg/ha whereas by 5.58 Mg/ha by delaying cutting intervals from every 28th day to 42nd day. Although harvesting alfalfa every 42nd day had the same cutting frequency as the 35th day treatment (i.e., 4 cuttings per year), the treatment harvesting every 42nd day had significantly higher alfalfa yield than 35th day cutting interval. Alfalfa yield increased by approximately 20% by delaying one week for harvesting alfalfa from 35th to 42nd day interval, based on dry matter yields of 2013 and 2014. As cutting interval increased from every 28th to 49th day, crude protein (CP) content decreased. In contrast to CP, acid detergent fiber and neutral detergent fiber increased as the cutting interval and stage of maturity increased in 2013 and 2014. The results suggest that alfalfa producers in Southwest Kansas possibly could reduce the cutting frequency from 5 to 4 per year. Cutting interval of every 42nd day between harvests appears to be the optimum when considered a dry matter yield and nutritive values in alfalfa.

Field performance of alternate wetting and drying furrow irrigation on tomato crop growth, yield, water use efficiency, quality and profitability

Sustainable irrigation method is now essential for adaptation and adoption in the areas where water resources are limited. Therefore, a field experiment was conducted to test the performance of alternate wetting and drying furrow irrigation（AWDFI） on crop growth, yield, water use efficiency（WUE）, fruit quality and profitability analysis of tomato. The experiment was laid out in randomized complete block design with six treatments replicated thrice during the dry seasons of 2013-2014 and 2014-2015. Irrigation water was applied through three ways of furrow： AWDFI, fixed wetting and drying furrow irrigation（FWDFI） and traditional（every） furrow irrigation（TFI）. Each irrigation method was divided into two levels： irrigation up to 100 and 80% field capacity（FC）. Results showed that plant biomass（dry matter） and marketable fruit yield of tomato did not differ significantly between the treatments of AWDFI and TFI, but significant difference was observed in AWDFI and in TFI compared to FWDFI at same irrigation level. AWDFI saved irrigation water by 35 to 38% for the irrigation levels up to 80 and 100% FC, compared to the TFI, respectively. AWDFI improved WUE by around 37 to 40% compared to TFI when irrigated with 100 and 80% FC, respectively. Fruit quality（total soluble solids and pulp） was found greater in AWDFI than in TFI. Net return from AWDFI technique was found nearly similar compared to TFI and more than FWDFI. The benefit cost ratio was viewed higher in AWDFI than in TFI and FWDFI by 2.8, 8.7 and 11, 10.4% when irrigation water was applied up to 100 and 80% FC, respectively. Unit production cost was obtained lower in AWDFI compared to TFI and FWDFI. However, AWDFI is a useful water-saving furrow irrigation technique which may resolve as an alternative choice compared with TFI in the areas where available water and supply methods are limited to irrigation.

Moderate wetting and drying increases rice yield and reduces water use, grain arsenic level, and methane emission

To meet the major challenge of increasing rice production to feed a growing population under increasing water scarcity,many water-saving regimes have been introduced in irrigated rice,such as an aerobic rice system,non-flooded mulching cultivation,and alternate wetting and drying(AWD).These regimes could substantially enhance water use efficiency(WUE) by reducing irrigation water.However,such enhancements greatly compromise grain yield.Recent work has shown that moderate AWD,in which photosynthesis is not severely inhibited and plants can rehydrate overnight during the soil drying period,or plants are rewatered at a soil water potential of-10 to-15 k Pa,or midday leaf potential is approximately-0.60 to-0.80 MPa,or the water table is maintained at 10 to 15 cm below the soil surface,could increase not only WUE but also grain yield.Increases in grain yield WUE under moderate AWD are due mainly to reduced redundant vegetative growth;improved canopy structure and root growth;elevated hormonal levels,in particular increases in abscisic acid levels during soil drying and cytokinin levels during rewatering;and enhanced carbon remobilization from vegetative tissues to grain.Moderate AWD could also improve rice quality,including reductions in grain arsenic accumulation,and reduce methane emissions from paddies.Adoption of moderate AWD with an appropriate nitrogen application rate may exert a synergistic effect on grain yield and result in higher WUE and nitrogen use efficiency.Further research is needed to understand root–soil interaction and evaluate the long-term effects of moderate AWD on sustainable agriculture.

Grain yield and water use efficiency of super rice under soil water deficit and alternate wetting and drying irrigation

This study investigated if super rice could better cope with soil water deficit and if it could have better yield performance and water use efficiency （WUE） under alternate wetting and drying （AWD） irrigation than check rice. Two super rice cultivars and two elite check rice cultivars were grown in pots with three soil moisture levels, well watered （WW）, moderate water deficit （MWD） and severe water deficit （SWD）. Two cultivars, each for super rice and check rice, were grown in field with three irrigation regimes, alternate wetting and moderate drying （AWMD）, alternate wetting and severe drying （AWSD） and conventional irrigation （CI）. Compared with that under WW, grain yield was significantly decreased under MWD and SWD treatments, with less reduction for super rice than for check rice. Super rice had higher percentage of productive tillers, deeper root distribution, higher root oxidation activity, and greater aboveground biomass production at mid and late growth stages than check rice, especially under WMD and WSD. Compared with CI,AWMD increased, whereasAWSD decreased grain yield, with more increase or less decrease for super rice than for check rice. Both MWD and SWD treatments and eitherAWMD orAWSD regime significantly increased WUE compared with WW treatment or CI regime, with more increase for super rice than for check rice. The results suggest that super rice has a stronger ability to cope with soil water deficit and holds greater promising to increase both grain yield and WUE by adoption of moderate AWD irrigation.

Influence of High Temperature Stress on Net Photosynthesis, Dry Matter Partitioning and Rice Grain Yield at Flowering and Grain Filling Stages

Climate change is recognized to increase the frequency and severity of extreme temperature events. At flowering and grain filling stages, risk of high temperature stress （HTS） on rice might increase, and lead to declining grain yields. A regulated cabinet experiment was carried out to investigate effects of high temperature stress on rice growth at flowering and grain- filling stages. Results showed that no obvious decrease pattern in net photosynthesis appeared along with the temperature rising, but the dry matter allocation in leaf, leaf sheath, culm, and panicle all changed. Dry weight of panicle decreased, and ratio of straw to total above ground crop dry weight increased 6-34% from CK, which might have great effects on carbon cycling and green house gas emission. Grain yield decreased significantly across all treatments on average from 15 to 73%. Occurrence of HTS at flowering stage showed more serious influence on grain yield than at grain filling stage. High temperature stress showed negative effects on harvest index. It might be helpful to provide valuable information for crop simulation models to capture the effects of high temperature stress on rice, and evaluate the high temperature risk.

Effects of Site-Specific Nitrogen Management on Yield and Dry Matter Accumulation of Rice from Cold Areas of Northeastern China

The effects of yield increase and mechanism of site-specific nitrogen management （SSNM） in five rice varieties from cold areas of northeastern China were studied. Plot experiment for critical SPAD value and experiments of two fertilization methods, SSNM and farmer＇s fertilization practice （FFP） were conducted to study their effects on the quality and dry matter accumulation of rice population, as well as N uptake. Compared with FFP, SSNM significantly decreased the average N rate by 33.8%, significantly increased average ear-bearing tiller rate and LAI for grain-filling stage by 12.3% and 14.1-27.6%, correspondingly, improved dry matter weight and N uptake after heading period by 4.3-29.1% and 11.8-55.1% （P 〈 0.05）, and heightened recovery efficiency and agronomic efficiency by 38.5-133.4% （P 〈 0.05） and 39.8-194.3% （P 〈 0.05）, respectively, as well as increased the average yield by 9.8% in 2004 and 2005. The results indicated that the accumulation rate of dry matter and N increased the rice yield and N use efficiency, because of improving rice population quality and increasing LAI after heading period.

Effects of Calcium Application Rate on Dry Matter Accumulation and Yield of Peanut

The effects of calcium application rate on dry matter accumulation and yield of peanut were studied under high-yielding field condition. The variety used for the study was Tang A8252( Spanish peanut). The results showed that number of full fruit,dry weight per plant,kernel yield,and pod yield all increased with calcium application increased,and they decreased when calcium application rate was more than150 kg/ha. Both the height of main stem and the length of side shoot decreased with calcium application increased. Therefore,to obtain the optimal agronomic character index and the highest yield benefit,the suggested calcium application rate would be 150 kg/ha for peanut.

Temporal Stability of Sward Dry Matter and Nitrogen Yield Patterns in a Temperate Grassland

The objectives of the present study were to examine the spatial patterns of sward dry matter (DM) and nitrogen (N) yields in a grass silage field at first, second, and third cuts over a 3-year period; quantify their temporal stabilities with temporal stability maps; and assess the potential for site-specific management in each pasture-growing period using classified management maps. At cut 1, the spatial patterns of DM and N yields proved to be well defined and temporally stable and were likely to be due to differences in the net N mineralization rates across the field during spring. In contrast, at cut 2, the patterns of DM production were patchy and temporally unstable. It was concluded that, in principle, a simple site-specific approach to N fertilization would be possible in this field during spring at cut 1. At later harvests, the rationale for a site-specific approach to fertilizer management was less clear with logistics appearing to be more complex and less feasible.

Soil tillage methods by years interaction for dry matter of plant yield of maize (Zea mays L.)using additive main effects and multiplicative interaction model

The objective of this study was to assess soil tillage methods by years interaction for dry matter of plant yield of maize(Zea mays L.) grown in West Poland by the additive main effects and multiplicative interaction model. The study comprised four soil tillage methods, analysed in 12 years through field trials arranged in a randomized complete block design, with four replicates. Dry matter of plant yield of the tested soil tillage methods varied from 86.7 dt ha(for no-plough tillage in 2005) to 246.4 dt ha(for complete conventional tillage in 2012), with an average of 146.6 dt ha. In the variance analysis, 49.07% of the total dry matter of plant yield variation was explained by years, 12.69% by differences between soil tillage methods, and 10.53% by soil tillage methods by years interaction. Dry matter of plant yield is highly influenced by soil tillage methods by years factors.

Effects of Different Ridge Culture Ways on Stem Diameter,Plant Height,the Number of Leaves and Yield of Phaseolus vulgaris L. under Dry Farming Conditions

The variety "Aifeng" was used as experimental material,and the stem diameter,plant height,the number of leaves and yield of P. vulgaris under three ways of ridge culture (bedding,high ridge and M ridge) were observed and detected to study the effects of different ridge cultures on the growth and yield. The results showed that the stem diameter,plant height,the number of leaves and yield under M ridge culture were higher than that of bedding and high ridge.

Comparative Effects of Cocoa Pod Husk and Oil Palm Bunch Ash on Nutrient Uptake, Growth and Dry Matter Yield of Cocoa (The-obroma cacao) in Ibadan, Southwest Nigeria

The high premium placed on the organically produced cocoa in the international market coupled with its health and environmental benefits necessitated recent focus on research into the use of agricultural wastes as source of nutrients in cocoa (T. cacao) production. The study was carried out at the Cocoa Research Institute of Nigeria (CRIN), Ibadan (Lat. 7&deg25'N Long. 3&deg25'E), South-western, Nigeria during the 2010/2011 seedling production season to compare the effects of NPK (20:10:10) fertilizer, Cocoa Pod Husk and Oil Palm Bunch Ash (CPHA and OPA) on the seedling growth and dry matter yield of cocoa (T. cacao). Equivalent amount of different rates of two nutrients sources CPHA and OPA were applied one month after planting at 0, 1, 2, 3, 4 and 5 t/ha respectively, recommended rate of 10 kg·N of the conventional NPK (20:10:10). Fertilizer was used as reference fertilizer. Results indicated that all the fertilizer materials positively and significantly (p > 0.05) increased the growth parameters considered. The influence of the ash materials irrespective of sources on the nutrient uptake, dry matter yield of cocoa seedlings and shoot to root ratio were either higher than or had a comparable results with the reference fertilizer (NPK 20:10:10). CPHA and OPA applied at a rate of 4 t/ha significantly (p > 0.05) increased the plant height and root length of cocoa seedlings respectively relative to control and in—organic fertilizer and could therefore be recommended for the prospective and existing Nigerian cocoa farmers for raising their seedlings in the nursery before transplanting to the field.

Effects of Limited Water Supply and Ridge Plotted Field on Soybean Yield and Dry Matter Accumulation

The drought in spring leads to the lack of soil water, which influents sprout and bud of crops, which furthermore affects growth and yield of crops. Studying the technology integration of bed-irrigating sowing, the mending irrigation of seedling stage and the effect of water-saving of ridge plotted field, analyzing the finger of yield and dry matter accumulation, water-saving technology integration have good effects on water-saving, water storage and increasing moisture on soil and enhancement of soybean yield.

Effect of Lime and Phosphorus on Yield and Yield Components of Groundnut Varieties [Arachis hypogaea L.] on Acidic Soil in Nedjo District, Western Ethiopia

Groundnut (Arachis hypogaea L.) is an important cash crop for smallholder farmers in western Ethiopia. However, the yield of the crop is very low mainly because of strong soil acidity and poor soil fertility management. A study conducted to evaluate the effect of lime and mineral phosphorus fertilizer on yield components and yield of groundnut. The treatments consisted of three phosphorus rates (0, 46 and 92 kg P2O5·ha-1), three lime rates (0, 6, and 11 ton lime·ha-1), and three groundnut varieties (local cultivar, Werer-961, and Werer-963) was laid-out as a randomized complete design in a factorial arrangement with three replications. The corresponding rates of phosphorus applied per pot of soil (7 kg) amounted to 0, 107 and 215 mg kg·soil-1 and those of lime amounted to 0, 14, and 26 g kg·soil-1. The analysis of variance showed that phenological characters, yield, and yield components significantly affected by interaction of variety, phosphorus, and lime. The highest dry pod yield produced by Werer-963 (2 kg dry pod yield·pot-1) in response to the application 11 t·ha-1 lime and 46 kg P2O5·ha-1. However, Werer-961 produced medium (1.5 kg dry pod yield·pot-1) at 11 t·ha-1 lime and 92 kg P2O5·ha-1 and the local cultivar produced minimum (1 kg dry pod yield·pot-1) at the application of 11 t·ha-1 lime and 92 kg P2O5·ha-1. In terms of phosphorus yield efficiency index, Werer-963 was highly efficient (index of 1.71), and Werer-961 was moderately efficient (index of 0.6). However, the local cultivar was inefficient (index of 0.04). It is at, in acidic soil of the study area Werer-963 is the best to be cultivated with application of lime 11 t·ha-1 and 46 kg P2O5·ha-1 fertilizer, followed by Werer-961. The results of this pot experiment have revealed that farmers in the study area need to switch to cultivating the improved varieties of groundnut rather than local variety with the application of high rates of lime and moderate amounts of phosphorus.

The heterotic effects on dry matter production and grain yield formation in hybrid rice

We studied the characteristics of dry matterproduction and matter partitioning in hybridrice and the relationships of them with heterot-ic effect in 1993. Two popular indica hybrids, Shanyou 63(Zhenshan 97A/Minhui 63 ) and Teyou 63(Longtepu A/Minhui 63), as well as theircommon restorer line, Minhui 63 (elite cultivar

干旱地区水盐胁迫对水稻产量构成及稻谷品质的影响研究

针对宁夏引黄灌区传统稻田蒸发量大,盐渍化耕地占地面积广、改良问题难,土地生产力下降等问题。采用水稻滴灌旱作方式,以富源4号(96D10)作为研究对象,通过设置不同土壤水分水平(W1:高100%、W2:中80%及W3:低60%田间持水率)及盐分水平(S1:轻1.2 g/kg、S2:中3.1 g/kg及S3:重5.3 g/kg),探究不同水盐胁迫对水稻产量构成及稻谷品质的影响规律。结果表明,水盐胁迫对水稻产量及品质具有较为显著的影响,其中产量构成因素中,千粒重W3S3较W1S1下降15.89%(2021年)和15.58%(2022年),饱籽率W3S3较W1S1显著下降3.45%(2021年)和4.05%(2022年),单位产量W3S3较W1S1显著下降56.48%(2021年)和63.09%(2022年);品质方面整精米率W3S3较W1S1显著下降12.65%(2021)和13.56%(2022),垩白米率W3S3较W1S1显著上升164.71%(2021)和122.73%(2022),直链淀粉含量W3S3较W1S1显著下降5.97%(2021)和8.99%(2022),蛋白质含量W3S3较W1S1显著上升53.51%(2021)和61.82%(2022)。综合考虑,在节水目标下,采用滴灌旱作方式种植水稻,保持80%田间持水率加轻、中度盐碱化(≤4.0 g/kg)的土壤环境,可以保持较为接近充分灌溉条件下的产量构成水平和较好的稻谷品质水平。该结论可为宁夏引黄灌区盐碱地可持续利用及水稻的节水灌溉适应性研究提供理论依据。

薯—稻轮作模式下播种密度对旱直播水稻产量的影响

【目的】探明高地力条件下旱直播水稻播种密度对群体质量和产量的影响。【方法】在云南省冬马铃薯—水稻(以下简称“薯—稻”)轮作高地力土壤上进行田间试验,以超级杂交籼稻F优498为供试品种,设置行穴距30 cm×13 cm(CK)、30 cm×11 cm(D1)、30 cm×15 cm(D2)、30 cm×17 cm(D3)和30 cm×19 cm(D4)共5种播种密度,比较不同密度对出苗质量、茎蘖动态、叶面积指数(leaf area index,LAI)、干物质积累转运特征以及产量及其构成因素的影响。【结果】随着播种密度的减小,有效穗数逐渐减少,单穴茎蘖数逐渐增加,每穗粒数显著增加,使总颖花量维持在4.4×10^(8)/hm^(2)以上。不同播种密度在维持适宜LAI的同时,随着播种密度的减小,齐穗后干物质积累量和积累率增加,提高了收获指数,从而使产量保持在较高水平(12.0 t/hm^(2)以上)。【结论】在薯—稻轮作模式下,将旱直播水稻播种密度调减至30 cm×19 cm,有利于齐穗后干物质的积累,增加每穗粒数,实现产量的稳定高效,并具有节本增效的作用。

龙菁1号紫花苜蓿新品种的选育

试验为解决寒区优质紫花苜蓿种质资源匮乏的难题,以抗寒、高产为育种目标,2002年起对9个国内外紫花苜蓿品种经过混合单株选择法及四代田间表型混合选择,选育龙菁1号紫花苜蓿品种。结果显示:在品种比较试验中,龙菁1号紫花苜蓿的干草产量、越冬率和粗蛋白含量最高,分别为10920.2 kg/hm^(2)、95.2%、19.22%;在区域试验中,龙菁1号紫花苜蓿在吉林白城地区的干草产量(11866.18 kg/hm^(2))最高;在生产试验中,与龙牧803、WL323HQ相比,龙菁1号紫花苜蓿在杜蒙地区的干草产量(10088 kg/hm^(2))最高。研究表明,龙菁1号紫花苜蓿品种的耐寒性、干草产量、粗蛋白含量均优于龙牧803和WL323HQ,是适合东北寒区人工草地建植、退化草原改良、粮改饲和草田轮作的优质牧草。

增密与减氮对青贮玉米产量的影响

以郑青贮1号、北农青贮368和郑单958为试验材料,研究了施氮量、种植密度及品种互作对青贮玉米鲜草产量和干物质生物产量的影响。结果表明:品种(郑青贮1号、北农青贮368、郑单958)、施氮量(N_(1)、N_(2)、N_(3)分别为240、216、168 kg/hm^(2))和密度(D_(1)、D_(2)、D_(3)、D4分别为6.75万、7.50万、8.25万、9.00万株/hm^(2))对青贮玉米干物质生物产量和鲜草产量均有显著的影响,在相同的密度水平下,3个玉米品种的干物质生物产量随施氮量的减少,总体呈下降趋势,但是N_(1)和N_(2)处理之间无显著差异;在相同施氮水平下,3个玉米品种的干物质生物产量随密度的增加,总体呈现先上升后下降的趋势;在不同施氮量和种植密度条件下,正常施氮量且高密度种植条件下(N_(1)D_(3)、N_(1)D4)的产量表现为郑青贮1号>北农青贮368>郑单958;在正常施氮量且低密度种植(N_(1)D_(1)、N_(1)D_(2))和减氮条件下(N_(2)、N_(3))的产量表现为北农青贮368>郑青贮1号>郑单958。因此,综合考虑减氮增产高效的目标,氮肥减施10%(N_(2))的条件下,郑青贮1号和北农青贮368的推荐栽植密度为8.25万株/hm^(2),郑单958不推荐作为青贮玉米种植。